Within the family at the center of Blue Heron, the black sheep is a blond. Fair-skinned teenager Jeremy (Edik Beddoes) is an outlier among his siblings, two jostling preteen boys and watchful, 8-year-old Sasha (Eylul Guven), who are all darkly featured and take after their Hungarian parents (Iringó Réti and Ádám Tompa). Jeremy’s hair color doesn’t really matter, of course, but the contrast makes a useful shorthand for Jeremy’s otherness. If “other” sounds inexact, that’s the point.